1. Field of the Invention
This invention relates to a process for the desulfurization of sulfur-containing compositions by hydrothermal reaction. By the process, it becomes possible to desulfurize fossil fuels, to eliminate harmful sulfur components at the time of preparation of polymers and to regenerate vulcanized rubber products. The invention also relates to a process for the conversion of vulcanized rubber products, such as tires, hoses and the like rubber articles, into oils for recycling purposes. The invention also relates to a catalyst which is useful for the oil conversion reaction of vulcanized rubber products.
2. Description of the Prior Art
As is known in the art, hydrodesulfurization processes have been widely used for purification and desulfurization. For instance, the pan process has been employed for the regeneration of vulcanized rubber. However, the known hydrodesulfurization processes have the problem that side products are produced and that when vulcanized rubber is regenerated, a sulfur component is inevitably left in the regenerated rubber. More particularly, the known processes are disadvantageous in the formation of side products and a low desulfurization rate.
In general, vulcanized rubber articles have been utilized as regenerated rubber, for example, according to the above-mentioned pan process wherein the crosslinkages are broken. Alternatively, vulcanized rubber articles have been merely burnt down in incinerators for recovery as thermal energy. The utilization of the vulcanized rubber articles as regenerated rubber means the re-use of the articles, but is not truly recycling them. On the other hand, the recovery as the thermal energy after combustion has the problem that the rubber articles are not utilized as a renewable resource with the added value not being high.